Once several cases of narcolepsy were documented in the late 1880s, study of the condition became more common. But it was well into the 20th century before sleep scientists really began to unlock some of the secrets of narcolepsy.

People were experiencing sleep disorders long before they were studied to the degree they are now. The first European account of narcolepsy appeared in the 1600s, but it would be well into the 19th century before the condition was researched.